Traction-engine.



B. Hom?,v TRACTION ENGINE.

APPLIUATION FILED JUNE 13, 1910.

Patented May 14, 1912;

2 SHEETS-SHEET 2.

BENJAMIN Bonn or sTocKTom'cALIFoRNIA.

TnAeTIoN-ENGINE.

Specification of Letters Patent.

'Patented May 14, 1912.

Y Application filed June 13, 1910. Serial No. 566,634.

To all wkomit muy concern.' Be it known that I, BENJAMIN HOLT, citizen of the United States,vresiding at Stock-A ton, in the county of San Joaquin and State of California, have invented new and useful Tmprovements in Traction-Engines, of

which the following is a specification.

'This .invention relates to wheel trucks,.

` and particularly to trucks for traction 1,0 engines adapted tbe propelled in conjunction with exible endless platforms. My invent-ion is designed .with the pur- 1 pose of providing an effective, resilient truck structure, particularly applica-ble -tol '1.5. the fra-me oftraction engines of the type which a're supported on and propelled by one Vor moreVv` flexible, endless, self-laying belt-tracks or traveling plat-forms, an object being to so connect the trucks yieldingly 20 to thel frame that a practically universal joint is obtained between each truck and the frame, thus measurably reducing the .great stresses presented by a stiff, non-yielding truck, and saving the gearfrom excessive wear; each truck being -entirely free from and independentof the other. n

The invention consists of the parts and the construction and combination of parts as hereinafter more -fully described and n claimed, having reference to the accompanying drawings, inwhich-w Figure 1 is a perspective view of the frame and truck, partly in section. Fig. 2 is a transverse section of the frame, showing the trucks in en d elevation. Fig. 3 is a side elevation-of the frame, truck and track. It .is a desideratum to obtain a truck structure for traction engines which operate in combination with flexible, endless tracks, 10 which will most successfully bear theA engine "\,frame and prevent the transmission of vibration and 'st-rain to the engine as the device travels over the ground, 'and which at the same time will affordV the' most effective', economical and practical voperative support to the tract-ion'belt platform, or self-laying trackfas it is'commonly designated.

Practical experience proves that a mostl c'licient combination comprises the organization herewith illustrated, in which Va suitable frame A is embodied, provision being made at B'for appropriate steering connections.

Adjacent to one end of the frame A and lriveted together; the rollers 3 being i parallel to its sides are trucksv 2 having 55 flanged rollers 3 arranged in pairsjadapted to support t-he back of the ground run of suitable endless,- linked tracks or belts 4. Each truck is in the farm substantially of an inverted channel made'ofr heavy steel plates 60 ournaled on pins 3 which extend througli the sides of the trucks, and each pair of wheels 3 having flanges which act as guides for the inner faces of the links of the track belts 4.

Each belt 4 is carried andpropelled by a suitable sprocket 5 and pulley-wheel 6 mounted on the frame and independent of its truck, andin the plane thereof, although in some cases the front idle wheel 6 may be 70 carried on the truck frame. The wheels 5 6 project between the rollers 3 of the truck, but out of interference therewith, land serve to hold the truck in parallelism with the frame. 7 5

Power to drive the sprockets 5 and belts may be derived from an engine (not shown) of appropriate style suitably mounted on the frame. In order to yieldingly supporttheI frame 80 so that the trucks may rock in a vertical plane conformable with t-he irregularities in Ithe surface of the roadway, without imparting the vibrations to the frame, suitable springs 7 are interposed between the trucks 85 andthe brackets 8 secured on frame A. These springs areonly designed and adapted to support the load on the trucks, and to absorb thegreater percentage of shocks incident to theV travel of the belts over the 90 I.

ground.

Each truck is arranged outside of the main frame and is located within the endless traction members or belts 4, andthe entire load is supported on the springs 7 and 95 trucks; the trucks being free to oscillate in vertical planes independent both of the frame and of the sprockets 5 and guide pulleys 6. Owing to the heavy weight, amounting sometimesV to several tons, which these trucks must support, and by reason of the length and shape of the trucks, the tendency of each truck to tip over and skid and to veer from the line of draft, is manifestly very great; and it is, therefore, t-oward the end of maintaining these trucks upright and parallel with the frame, that the present invention is particularly directed. lAs

-of accomplishing the desired result. y

As here shown, the top plate 9 of each truck has an inwardly extending, horizontrucks to tip sidewise and tal, triangular projection 10 forming a reinforcing bracket or brace for the anglebars 11 which are bolted crosswise of the truck to the plate 9 and its extension l0; there being a pair of these ,angle-bars 11 for each truck, constituting a radius arm and support for the-truck, and the inner end of the arm having a loose, swiveling, pivotal connection, at 12, onsome suitable portion of the engine frame, as, for in stance, thedrop hanger and cross-brace 13. Each truck is thus pivoted direct to the frame by an offset lateral connection, andthe pivot 12 is loose enough to allow for a truck to rock independently in a plane parallel with t-he length of the frame. The arms 11 are rigidly connected to ,each truck 4and eX- tend inwardly and pivot inthe manner described and efectually operate to prevent the trucks from tipping over. The rigid connection of the arms 11 with the trucks is essential, as otherwise the ground run of the-traction member a and the bottom of the truck would skid or get out of vertical alinement.

Since the weight of the vehicle is supported entirely onthe trucks, and as .these machines are often v very heavy, and the Vweight may or may not be carried over the center. of the trucks, the tendency of the trucks to turn sidewise or `to skid .fromy under the machine is very great, as prevlously stated. The flanges on the wheels 3 keep the ground run of the traction member always in the plane of the trucks, while the rigid arms 11 with their pivotal connections 12 maintain the trucks always vertical and yet allow lating movements` The tendency of the the belt to skid is particularly great in turning corners, by reason of the long frictional bearing surface that-- the tread member has on the ground.

In order to prevent longitudinal movement of the trucks in ependent of the frame, and relieve the springs of lateral vstrain or twist, I employ the links or pivot bars 14; the backward thrust of the trucks, due to the travel ofthe traction member, being resisted by these -pivot bars. At the same time, these pivot bars permit of the desired undulating action of the. truck and ground run of the'traction belt.

the actual construction of these.

for the necessary undu-.

The loose intermeshin of the wheels 5 6 with the ends of eac truck and with the front and rear sets of rollers 3 will serve to keep the trucks parallel with the frame. .Y

The construction here described of so connecting the trucks to and supporting them from the frame, that each may yiel practically independently of the other -and of the frame, is important, .especially in traveling over rough roads or land, where each track belt encounters irregularitiesdifferent from-the other, and where the trucks are constantly rockin and assuming opposite ,or dierent ang es.

Having thus described my invention, what I claim and desire to secure by Letters Patent is- Y 1. The combination with a main frame, of flexible, endless traction members, trucks located within said members, sprin the trucks and frame and yieldingly supporting the latter, and means for maintaining said trucks upright, said means includ- 'ing a transversely extending arm on each truck and rigidly secured thereto, with the free ends of said arms pivotally supported on the frame, so that each truck is free to rock and move in a vertical plane.

2. The combination of a Amain frame and iexible endless traction belts, trucks outside of and having. means for yieldingly. supporting the frame and `around which thel traction belts travel, transverse connections' between the central .part of tle4 frame and each truck, said transverse'connections havbetween ing a vpivotal connection with the frame and" a rigi .connection with its truck to permit the trucks to tilt independently of', each 5 other.

3. The combination of an engine frame,

a iexible, endless track, a truck bearing.

oy transverse rigid brackets to said frame,

'and rollers on the trucks resting on the ound runof the tracks, said rollers and wheels on the-frame being interlapped.

5. The combination lwith a main frame, vof parallel, endless, iexible tracks, trucks disposed within said tracks, rollers journaledin said trucks and supported on the ground run of said tracks, and wheels supported on the main frame and laround which the flexible tracks travel, and certain of said 115 iexible tracks, wheels on the frame wheels interlapping the rollers, whereby the 13C trucks are prevented from twisting 'siderigidly secured to the trucks and projecting wise. laterally toward and pivoted to the frame. 6. The combination with a main rame,of Y In testil'no'ny whereof I have hereunto set traveling, endless, flexible tracks, driving my hand in the presence of two subscribing 5 wheils theiefor h theil frarine, tiucks fwithwitnesses. I

-in t e trac s an at t e si es o the rame f and having ineans for 'yieldingly spport- BENJAMIN HOLT' ing the frame, so'that the trucks may rock Witnesses: in vertical plane, and connections between P. S. SPRINGER, 10 said trucks and frameincluding angle-bars H; E. THRELFALL. 

